To collect data related to beacon transmitters (for example, Bluetooth (BT) or WiFi Access Points (APs)) a mobile device may use passive scanning techniques comprising periodic scans to sample beacon data. For example, the process of discovering/mapping beacon positions within an indoor environment can include scanning WiFi APs to retrieve MAC addresses, Received Signal Strength Indication (RSSI), Round Trip Time (RTT), or other beacon measurement data. In addition to scanning WiFi APs or BT transmitters, a mobile device may also estimate its own location (for example, upon getting a Global Network Satellite System (GNSS) fix of the mobile device) and attempt to associate or tag the beacon data with the mobile device location. In response to filling a local buffer with beacon data, the mobile device may send the beacon data and any associated location data to a server for processing and mapping of beacons. However, beacon data sent to the server may include erroneous or irrelevant mobile location or beacon data. Also, the mobile device may continuously send data regardless of whether the server has a specific request for the beacon data. A mobile device may therefore sometimes report too much beacon data and all of the reported data may not be entirely relevant or accurate. Therefore, new and improved beacon data collection techniques are desirable.